Starting device for internal combustion engines



W. B. SMITS Jan. 29, 1957 STARTING DEVICE FOR INTERNAL COMBUSTION ENGINES 2 Sheets-Sheet 1 Filed' March 51, 1952 II I INVENTOR draw? ATTORNEYlfi 2 Sheets-Sheet 2 W. B. SMITS Jan. 29, 1957 STARTING DEVICE FOR INTERNAL COMBUSTION ENGINES Filed March 51, 1952 INVENTOR ATTORNEKE ail...

United States STARTING DEVICE FOR INTERNAL COMBUSTION ENGINES Application March 31, 1952, Serial 279,675

r 2 Claims. or. 315-412 The invention relates to a starting device, fed by a separate current supply, battery, or the like, for internal combustion engines, which are equipped with low tension surface discharge spark plugs, in which one or more condensers are charged by means of magnetic field alterations.

Several starting devices for internal combustion engines are already known.

For high tension equipment, in which a high voltage is generated in the secondary winding by the opening of a small contact hammer in the primary winding at the moment of alteration of the magnetic field, at low speeds such as occur during starting, the voltage thus generated is too slight to cause a sufficiently strong spark to jump between theelectrodes of the spark plug. In order to obtain a sufficiently strong spark, certain expedients are employed, which may consist in a separate buzzer coil operating on a battery, which passes high tension sparks to the spark plugs. This has the drawback that a separate coil is required and also that the formation of a spark prior to the right moment of ignition must be prevented. To achieve this, the energy is discharged for a long time to the ground, and is not passed to aspark plug until the right moment, so that about 75% of the high tension energy is lost.

Sometimes use is made of the primary winding itself, through which a current is driven which is periodically interrupted by a separate interrupter. In this case, however, the current must be a strong one, since with each interruption a high tension spark of sufficient energy must be formed. The risk of demagnetization of the permanent magnet is possible with the field intensities here occurring.

Further, starting devices are known for equipment in which owing to the field alteration a sufiiciently high voltage is generated in one of the windings to enable one or more condensers to be charged with this voltage via one or more rectifying valves or spark gaps, with the aid of a special connection, and in which after the charging the discharge is effected by the switching in of a surface discharge spark plug. These starting devices feed the condensers with a separate connection, independent of the ignition system itself. It is also known that if it is desired to stop a rotating engine, this can be done by means of a primary winding. This winding is short-circuited by means of a short-circuit switch, as a result of which the generation of the voltage in the secondary winding is disturbed.

The consequence of this is that no ignition spark is now formed or that it is weakened to such a degree that the spark is no longer capable of igniting the gas mixture.

According to the invention this thicker winding, the socalled stop winding, is retained and is used as primary winding, through which are driven voltage impulses which generate in the secondary winding higher voltages, which are capable of charging the condenser or condensers. By a temporary switching in of a second condenser, the starting capacity can be raised even more. For this,

atent O series of sparks at the surface discharge spark, plugs.

In consequence .of this, the gas mixturetis ignited, the engine begins to rotate and assoon as through the alterations of the poles a suificiently high-voltage is generated in the, secondary winding for it to take over the,

charging, the pulsatory current source is disconnected in some way or other. Since the whole interval between two discharges can now be turned to account for the charging of the condenser or condensers, a much weaker current is required, as a result of which the intensity of the field is much lower, so that the risk of demagnetization is minimized.

According to the invention, a second condenser can be connected in parallel with the ignition condenser, as a result of which a particularly large ignition spark is formed, which is especially important when the system is used in very cold regions since the ice formed on the electrodes of the spark plugs can be broken up by it.

The invention is explained more in detail with reference to the drawing illustrating an embodiment.

Fig. 1 is a circuit diagram of one embodiment of the present invention, and

Fig. 2 is a circuit diagram of another embodiment.

Fig. 1 of the drawing shows the circuit diagram according to the invention, in which 1 is the primary winding of a megneto and 2 the secondary winding. One end of the primary winding 1 is connected to a switch arm 3, which co-operates with a contact 4, the so-called stop-contact, and with a contact 5, the so called startcontact. This start-contact 5 is connected via a conductor 6 to a common conductor 7, which is grounded at 14.

From the conductor 7, a conductor 8 leads to the magnet 9 of a vibrator, which is provided with an armature 10 controlling two contacts 11. In order to prevent spark formation, a condenser 12 has been connected in parallel. This primary connection is fed by a battery 13, and it is obvious that when the switch arm 3 is connected to the start-contact 5, pulsatory current impulses are generated in the primary winding 1, which impulses produce current impulses of higher voltage in the secondary winding 2. These current impulses are provided via the rectifying system 15 to the ignition condenser 16, which is connected to the distributor arm 17 contacting the distributor contacts 18, which are connected to the ground via the spark plugs 19.

During the turning of the distributor arm 17 the condenser 16 has an opportunity to become charged, and while contacting one of the distributor contacts 18, the condenser 16 will discharge via the corresponding spark plug 19.

Fig. 2 illustrates the same circuit diagram, but in this case a second condenser 20 is connected in parallel, so that upon the switch arm 3 being placed in the starting position, this condenser is at the same time switched in via 5.

It should be noted that the device can also be constructed to include several discharging condensers, that several contacts may co-operate, with the result that several primary windings of several magnets are operated simultaneously.

Further, the two primary windings may be connected in parallel from a source of current, .so that current impulses are simultaneously generated in both magnets. The same result is obtained when the primary windings Patented Jan. 29, 1957 of-t-he two magnets or, if desired, of several magnets are connected in series.

I claim:

1-. An ignition circuit-for a combustion engine eom pri'singan ignition condenser, a discharge path'for' said ignition condenser including a plurality'ofilow voltage surfiace discharge spark plugs and adi st'ributor' for periodically connecting said ignition condenser with each of said spark plugs, a magneto having primary and secondary windings, the'secondary winding being connected in a charging circuit for said ignition condenser, a

source of pulsating current, switch means adapted to connect said source of pulsating current with the-primary winding to start the engine, saidswitch means adapted" to shortcircuit the primary winding to stop-the engine and adapted to interrupt the circuit of the primary winding.

2. A circuit according to claim 1 and further including a second condenser in parallel with said ignition condenser.

References Cited in the file of this patent UNITED STATES PATENTS 

